In 2011, the Intergovernmental Panel on Climate Change (IPCC) released its Special Report on Renewable Energy Sources and Climate Change Mitigation, or SRREN. The report sought to determine the potential contribution of renewable energy sources to the mitigation of climate change. It reviewed the results from 164 individual scenarios derived from 16 different models, all developed since 2006.

For some, the report’s conclusions were sobering: nearly half of the scenarios suggested that renewable energy sources might contribute no more than 27% of the world’s energy supply by 2050 (see Chapter 10, p. 794). Even when counting only the most aggressive scenarios — the ones where atmospheric CO2 concentrations are stabilized to less than 400 parts per million — the median estimate of world’s renewable energy supply in 2050 was somewhat less than 250 exajoules; or, in other words, about half of global primary energy consumption today.

The report is by no means overly critical of renewables. For example, its rather loose definition of renewable energy includes “traditional” biomass, the main cause of deforestation, and the feasibility of various scenarios is never assessed in the report: no evaluation whatsoever is conducted to determine which of the 164 scenarios might be realistic, and which may be not. Nevertheless, the results show clearly that renewable energy sources are highly unlikely to be enough for meaningful climate change mitigation, even if energy efficiency takes leaps and strides.

It is therefore very instructive to note how various anti-nuclear groups have chosen to portray the results. Without exception, and perhaps mislead by SRREN’s extremely skewed press release, every anti-nuclear organization I’ve so far researched tells you that IPCC SRREN “proves” or “shows” that a future powered completely by renewables is completely possible.

For just one example, take this statement from Greenpeace:

“According to the IPCC’s ‘Special Report on Renewable Energy Sources and Climate Change Mitigation’ (SRREN), by harnessing just 2.5% of viable renewable energy sources, with currently available technologies, its possible to provide up to 80% of the world’s energy demand by 2050.” (Source)

This, my friends, is cherry-picking pure and simple. What anti-nuclear activists don’t tell you is that only two of the 164 scenarioscould in any way be construed to suggest anything like that. What’s more, the 80% claim comes from Greenpeace’s Energy Revolution scenario. One could take issue with the fact that in reality, it’s largely prepared with data and “assistance” from renewable industry lobby group EREC, but industry biases and other oddities aside, this scenario assumes that world energy use actually decreases from current levels — even as the world’s population grows to 9 to 10 billion and there are no signs whatsoever that developing nations are willing to forgo the fruits of high-energy lifestyle.

This is so important that it bears repeating: At most, 1.2% of scenarios find that less than 80% of the energy world uses today might be possible to generate from renewable sources alone. The remaining 98.8% aren’t so sanguine.

And, again, that’s with current consumption levels, when the broad consensus is that world’s primary energy demand will increase greatly over the next few decades.

Sure, technically speaking anti-nuclear organizations are correct: it might be possible to derive 80% of world’s energy from purely renewable sources, in the “best case” scenario. But omitting crucial details and the gist of the report are wanton acts of cherry-picking and demagoguery; it’s the exact equivalence of claiming that CO2 emissions aren’t harmful — if all the known and suspected feedback mechanisms turn out to cancel the effects of increased emissions.

What the SRREN report actually shows is that in practice, renewables alone are highly unlikely to be enough, fast enough, to avert the coming climate catastrophe. Similar results abound; to pick just one example, let’s check the recent modeling work undertaken for a book by Mark Lynas. It shows rather clearly that even the aforementioned Greenpeace’s EREC’s Energy Revolution would be highly likely to fail in keeping the global warming below 2°C — even if the scenario were to be executed in full, without fail, starting today.

So, here’s the question: what should we call those who cherry-pick the climate science to suit their political agenda?

Frankly, the problem with this report is that it does not delve into the real issue: what scenario is the most probable one, country by country? It does not because it’s all about politics, which is not the realm of the IPCC. Gathering a number of scenarios does not mean any of them will be realized: I do not think any of these scenarios are limited by anything else than the hypotheses of the authors.

In the end this report is a tour of the various scenarios which concludes that CO2 emission would be curtailed if only we would use less energy and use only renewables. Stunning. By its bullishness, the press release reflects more or less the opinions of the lead authors. In a field so close to politics, I’m not surprised.

I must say that I am not very convinced of the usefulness of the IPCC’s WG3 (about mitigation): it’s too close to politics. WG1 is pretty much unassailable, WG2’s task is a bit more complicated because it’s about the future, but it’s still a direct application of the climate models. WG3 on the other hand is all about policy prescriptions, which have no real chance to be consensual if they’re not obvious.